Tire Scouter

315/45R21 tires

Compare 2 models made in this size across 2 categories, ranked by spec score, then confirm fitment for your vehicle.

Spec scores are estimates from five manufacturer specs, not road tests. How we score

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Our top pick in 315/45R21

Continental PremiumContact 6

  • Max performance summer

Best for enthusiast drivers.

The PremiumContact 6 is a strong choice for drivers who prioritize grip and handling in both dry and wet conditions.

  • Dry grip score of 9, which is above the category average of 8.2, making it a strong performer in dry conditions.
  • Wet grip also scores a 9, exceeding the average of 7.9, ensuring reliable performance during rain.
  • Handling is rated at 9, indicating precise response and control, which is crucial for spirited driving.
Full analysis

The highest spec score among max performance summer tires in this size that we have analysis for, the most common category for 315/45R21.

79Strong
None listed
280
AA
Y · 186 mph

Every scale below runs from the lowest to the highest spec score among the 1 scored tires in 315/45R21 (79 to 79).

Best max performance summer tires in 315/45R21

1 model, highest spec score first.

All max performance summer tires

  1. Continental PremiumContact 6

    Best for enthusiast drivers.

    79StrongFrom 4 of 5 specs
    Warranty
    None listed
    Treadwear
    280
    Traction
    AA
    Speed rating
    Y · 186 mph
    • Dry grip score of 9, which is above the category average of 8.2, making it a strong performer in dry conditions.
    • Wet grip also scores a 9, exceeding the average of 7.9, ensuring reliable performance during rain.
    • Average comfort and noise scores may deter those looking for a quieter, more comfortable ride in a max performance summer tire.

Best winter tires in 315/45R21

1 model, highest spec score first.

All winter tires

  1. Pirelli Scorpion Winter

    Severe-snow rated

    Best for winter highway commuters.

    Not enough spec data
    Warranty
    None listed
    Treadwear
    Not graded
    Traction
    Not graded
    Speed rating
    V · 149 mph
    • 60,000-mile treadwear warranty exceeds the winter category average of 54,431 miles, offering longer usage before replacement.
    • Snow traction score of 8 matches the category average, ensuring reliable performance in typical winter conditions.
    • Lack of ice traction data may be a concern for those facing frequent icy conditions.

Popular brands in 315/45R21

The number beside each brand is how many of its models come in this size.

What 315/45R21 means

315/45R21 designates a tire 315 mm (12.4") wide with a sidewall 45% as tall as it is wide — about 142 mm (5.6") — mounted on a 21-inch wheel. That works out to an overall diameter of roughly 32.2", a circumference of about 101.0", and approximately 627 revolutions per mile. Exact figures vary slightly by manufacturer and tread design.

Of the 2 315/45R21 tire models we track, the most common category is max performance summer (1 model), followed by winter (1) — a good indicator of the kind of vehicles and driving this size is designed for.

Sidewall height
142 mm
Overall diameter
32.2 in
Circumference
101.0 in
Revs per mile
627

Frequently asked questions

What does 315/45R21 mean?

315/45R21 breaks down as follows: 315mm is the tire's section width (the widest point), 45 is the aspect ratio (sidewall height as a percentage of width), R means radial construction, and 21 is the wheel diameter in inches.

What vehicles use 315/45R21 tires?

315/45R21 is a standard tire size found on many trucks, SUVs, and crossovers. Use our vehicle search to confirm your exact fitment.

How tall is a 315/45R21 tire?

A 315/45R21 tire has a sidewall height of about 142 mm (5.6") and an overall diameter of roughly 32.2", turning approximately 627 revolutions per mile. Actual dimensions vary slightly by manufacturer and model, so confirm against your vehicle's placard before changing sizes.

315/45R21 research guides

Summer vs all-season tires

Where summer tires lose grip, the cold-cracking risk, and what all-season tires trade for their range.

Read the guide

Speed rating chart

A practical chart for common tire speed ratings and what they mean for everyday driving.

Read the guide

Changing tire size

Plus-sizing and alternate sizes: diameter limits, load and speed ratings, and speedometer error.

Read the guide

Confirm 315/45R21 fits your vehicle

Wheel size can vary by trim and option package. Enter your year, make, model, and trim to verify fitment before you order.

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